Arabidopsis trichomes (hair cells) respond to mechanical stimuli by initiating potential signaling factors in themselves and in the neighboring cells. These vibrational responses of Arabidopsis trichomes support the hypothesis that trichomes respond acoustically to vibrations associated with feeding caterpillars. Trichomes have vibrational modes in the frequency range of the sounds of feeding caterpillars, encouraging further experimentation to determine whether trichomes serve as mechanical antennae. Arabidopsis plants have been reported recently to react to the sounds of caterpillars of Pieris rapae chewing on its leaves by promoting synthesis of toxins that can deter herbivory. Identifying leaf trichomes as acoustic antennae of plant cells suggests potential “ears” of Arabidopsis.
A new study published in Annals of Botany has shown that plants react to anaesthetics in a similar way to animals and humans, suggesting plants are ideal objects for testing anaesthetics actions in future.When exposed to anaesthetics, a number of plants lost both their autonomous and touch-induced movements. Venus flytraps no longer generate electrical signals and their traps remain open when trigger hairs were touched, and growing pea tendrils stopped their autonomous movements and were immobilized in a curled shape. The results of this study suggest that the action of anaesthetic at cellular and organ levels are similar in plants and animals.
Nectar robbing bumblebees are detered from visiting and feeding from Aconitum flowers via alkaloids which are more distasteful to nectar robbers than to pollinating honeybees. Obviously, plants can finely control behaviour of insects using mixtures of alkaloids and other non-nutrient compounds enriched within their nectar exudates.
Plant microRNAs control honeybee caste development by preventing larval differentiation into queens and inducing formation of workers. Especially important in this respect is miRNA162a which targets genes of the TOR complex. Previously, dietary plant microRNAs were reported also in human blood but possible impacts on humans are still not clarified.
Tomato plants attacked by small mottled willow moth caterpillars release chemicals with turn these caterpillars into cannibals. This plant induced caterpillar cannibalism benefit tomatoes in two different ways. Firstly, cannibalism directly reduces vegetarian caterpillar abundance. Secondly, cannibalistic caterpillars eat significantly less tomato leafs.
Growing roots locate a water source by sensing the vibrations generated by water moving inside pipes, even in the absence of substrate moisture. When both moisture and acoustic cues were available, roots preferentially used moisture in the soil over acoustic vibrations, suggesting that acoustic gradients enable roots to broadly detect a water source at a distance, while moisture gradients help them to reach their target more accurately.